Asphalt concrete fatigue cracking is recognized as a major distress mode in the U.S. The widespread nature of this distress and the data from agency Pavement Management Systems (PMS) suggest that it is an issue with asphalt mixture design and production processes and is not a problem specific to certain...
Reusing reclaimed asphalt pavement (RAP) presents an opportunity to reduce environmental burdens and encourage sustainable development. However, a concern exists about blending RAP binder and virgin asphalt binder. While RAP mixtures assume complete blending between these binders, the actual extent of this blending remains uncertain. Lower blending percentages can reduce...
Bridges are a vital component of transportation infrastructure in the United States, and the continual maintenance and preservation of bridges is critical to maintaining their structural capacity and maximizing service life. One of the most significant issues faced by concrete bridges is the infiltration of moisture from the roadway surface...
Tack coat emulsion, comprised of asphalt binder, water and emulsifying agents, is an interlayer membrane applied before asphalt pavement construction, which helps pavement layers bond together and permeate stresses and strains induced by heavy wheel loads through the entire thickness of the pavement structure. Proper interlayer bonding aids in preventing...
The resistance of asphalt concrete pavement to distresses such as fatigue cracking and permanent deformation is governed by how well the structure can resist loading under a variety of traffic and climate-related conditions. Asphalt binder type and content are typically the variables that pavement engineers can manipulate to render the...
Asphalt pavements constitute more than ninety percent of the nation’s roadway network. Besides serving the key role of providing a smooth and durable all-weather surface that benefits a range of users, they are also the lifelines of the nation and the world and contribute tremendously towards economic and social development....
Decreases in pavement program funding levels have encouraged paving agencies to adopt higher levels of recycled materials into their asphalt mixes. In order to fully evaluate the effects of recycled asphalt pavement (RAP) in Hot Mix Asphalt (HMA) mixes, the level of blending between the RAP and virgin binders in...
CSS-1H is the most commonly used slow-setting emulsion grade in Oregon. “New” engineered emulsions were recently developed in Oregon to reduce tracking, the pick-up of tack coats by construction vehicle tires during construction activities, and increase interlayer shear strength (ISS), the amount of adhesive bond present between layers of asphalt...
Concrete has been categorized as a key contributor of CO2 (carbon) emissions into the atmosphere. This is mostly associated with the production of ordinary portland cement (OPC). The concrete and cement industries are pursuing a path to reduce their carbon emissions generally in accordance with the climate change goals outlined...
Flexible pavements consist of multilayers, which form the pavement structures. Since the strength of the bond at interface between layers plays a significant role in improving the structural integri-ty and the performance of pavement structures, tack coat materials and methods used for their application during construction are important in providing...